read sumproduct explained

http://www.xldynamic.com/source/xld.SUMPRODUCT.html

--


Gary


"christian_spaceman" wrote in message
ups.com...
Hi,

Quick question really... I wanted to 'countif ' with several criteria
and found the following on the mr excel boards:

=SUMPRODUCT(--(B1:B1000="Chris"),--(C1:C1000="working"),--
(D1:D1000="laptop"))

(it counts the rows which have Chris working with a laptop).

It worked really well, but I've been unable to find a description of
the -- operator? (neither the help nor google have been able to help
me so far...)

Could anyone enlighten me?

Thanks in advance,

Chris